Taller 5th gear?

I'll start by introducing myself... Names Anthony Russo, was an avid dsmer from 01-06 when I gave up the hobby to attend college. Now that I'm graduated w/o a job buying a new car was not an option. Nov 09 I was searching for early-mid 90's 5spd sedans, stumbled upon a 91 summit white galant (#110/2k I think, no badge/fob?) didn't seem like too bad of a car so I snatched it up for just under $2500. And my gvr4 journey began LOL

Anyway, I'm replacing my less than fair condition trans for a freshly rebuilt DogBog racing stg3 trans, all new evo3 gears, double syncros, 4dpider diff, ect. I do ALOT of driving in #110, I really want too have a 10% taller 5th gear I found on JacksTransmissions site ($200) installed by DogBox being that thy are very local. Does anybody use a taller 5th gear other than for trapping 180+mph? I heard some machining is required? Any MPH and/or RPM comparisons over stock 5th? Any feedback/input would be greatly appreciated!

Thanks!
Anthony Russo

 

[trunks]

I've got it in my 2g and I see about 300 less rpms in 5th gear. So 60 mpg is running about 2500 rpms. I get about 21 mpg avg with e85 with it in there. It was direct replacement for a 2g transmission but I'm not sure with a 1g tranny. The toughest part was getting the old 5th gear out. I used the coin trick between the geas thats I read somewhere but went through quit a few coins before I could get that nut loose.

 

[Terry Posten]

The 10% taller gear is a direct swap in and can be done just by pulling the back cover and an impact to get the nut loose. The larger ones need to have the case milled.

You may see 2-3 mpg more with the 10% taller gear. But if you get the revs below the power band, you will burn more fuel lugging the motor.

 

You should NEVER EVER use and impact to break that nut lose. It will shock load the gear set and break them or chip them.

You can tap out the roll pin that holds the fifth and reverse fork on and engage fifth gear and engage third and that will lock the trans so you can unstake the nut and loosen the nut with a breaker bar. The torque on that nut is 105 ft. lbs. when going back together.

 

Also like Terry said, you the EVO III (10% taller) fifth gear is a direct swap. TRE did make a 25% taller straight cut gear that is no longer available. I have one in my 2g eclipse and its almost too tall like Terry said, I think I burn up more gas with the 25% taller one than the Evo III fifth gear did.

I think i'm just going to put the stock one back in.

 

[Terry Posten]

Quoting BOOSTIN HARD:
You should NEVER EVER use and impact to break that nut lose. It will shock load the gear set and break them or chip them.



Now you know why I paid Chris to build my EVOIII box. I always seem to make 1 little mistake.

 

Awesome, thanks for all the helpful info guys!!! I'm def going with the EVO3 5th gear-set from JacksTrans. I think it's like $221, does that sound right? Any chance of finding it cheaper?

Thanks Again!
Anthony